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SAE J851‑2011: Dimensional Standards for Truck and Bus Wheels, Demountable Rims, and Spacer Bands
SAE J851‑2011 is a stabilized recommended practice that establishes the critical dimensions for wheels designed for demountable rims, demountable rims themselves, and rim spacers (spacer bands) used in truck and bus applications. These dimensions are essential for maintaining serviceability and interchangeability across manufacturers and service operations.
Scope and Stabilized Status
The standard covers common wheel‑and‑rim configurations for commercial vehicles. It does not address special or less common designs. Key dimensions are provided for front and rear wheels, multi‑piece flat base rims, full drop center rims, and rear wheel spacer bands.
⚠️ Stabilized Standard Notice
The SAE Truck and Bus Wheel Committee has determined that SAE J851‑2011 contains mature, stable technology. The document is no longer subject to periodic reviews, and users must verify that the requirements remain suitable for their specific applications. Newer technologies may exist that are not reflected in this standard.
The SAE Truck and Bus Wheel Committee has determined that SAE J851‑2011 contains mature, stable technology. The document is no longer subject to periodic reviews, and users must verify that the requirements remain suitable for their specific applications. Newer technologies may exist that are not reflected in this standard.
Critical Dimensional Specifications
The standard defines several reference dimensions for wheels (A, B, D, W, L, d₁), for demountable rims (C, E, L₁), and for spacer bands (F). Each dimension is assigned a tolerance to ensure interchangeability while allowing manufacturing variation.
Wheel Dimensions (partial)
| Rim Size | A (Rim mounting dia.) +0/–0.015 |
B (Wheel outside dia.) +0/–0.030 |
W (Bevel width, min) | L (Rim locator width, min) |
|---|---|---|---|---|
| 15 × 8.0 Max | 13.550 | 14.365 | 2.00 | 3.90 |
| 22 × 8.0 Max | 20.550 | 21.365 | 2.75 | 4.60 |
| All 22.5 | 18.550 | 19.365 | 2.50 | 3.90 |
| 24 × 8.5 to 10.0 | 22.422¹ | 23.281 | 2.75 | 5.40 |
| ¹ Tolerance +0/–0.023 for this size. All dimensions in inches. For complete data consult the standard. | ||||
Demountable rim dimensions include the cylindrical gauge diameter (C), bevel location (E), and valve locator width (L₁). Spacer bands for rear wheels are defined by inside diameter (F) with a +0.094/–0 tolerance to ensure concentric alignment.
🛠️ Engineering Design Insight
When selecting or designing wheel‑rim‑spacer systems, pay close attention to the bevel width (W) and rim locator slots (L). These features determine how the rim seats on the wheel. The tolerances are intentionally set with only plus‑zero/minus values to guarantee minimum clearances and proper load transfer. For double bevel rims, bolt circle diameter (D) may deviate from the front/rear values shown in Table 1—always verify the notes in the standard.
When selecting or designing wheel‑rim‑spacer systems, pay close attention to the bevel width (W) and rim locator slots (L). These features determine how the rim seats on the wheel. The tolerances are intentionally set with only plus‑zero/minus values to guarantee minimum clearances and proper load transfer. For double bevel rims, bolt circle diameter (D) may deviate from the front/rear values shown in Table 1—always verify the notes in the standard.
Engineering Considerations and Frequently Asked Questions
Below are some common questions engineers face when working with SAE J851‑2011.
What does the stabilized status mean in practice?
The standard is no longer updated, so you must independently confirm that the dimensional requirements are still compatible with your current manufacturing processes, materials, and safety standards. It may be advisable to check for newer applications that require tighter tolerances or different interfaces.
How do front and rear wheel dimensions differ?
Front and rear wheels share the same mounting diameter (A) and outside diameter (B) for a given rim size, but the bolt circle diameter (D, reference) can differ, particularly for larger rims (e.g., 24×10.0). The standard provides separate reference columns for front and rear D values.
Why are tolerances given as +0/–?
This unilateral tolerance scheme ensures that the actual dimension never exceeds the specified maximum, guaranteeing that components will fit together. The minimum clearance or interference is thus maintained even with worst‑case manufacturing variations.
How does this standard relate to SAE J393 and SAE J1835?
SAE J393 defines nomenclature for wheels, hubs, and rims, while SAE J1835 specifies fastener hardware for demountable rims. SAE J851‑2011 covers the dimensional requirements; together these standards form a complete framework for commercial vehicle wheel systems.
For further details, refer to the full SAE J851‑2011 document. Always verify that your application falls within the scope of this recommended practice and consider any newer technologies that may offer improved performance.
